Corrosion Bacterias acero 316L, analisis .pptx

Exposicion corrosion por bacterias

1. The corrosion of 316L stainless steel induced by methanocossus mariplaudis through indirect electron transfer in seawater Presented by: David Andrés López Sáenz. 201720465. Juan Diego Nuñez Amaya. 201720457.

2. Microbiologically influenced corrosion (MIC) refers to the corrosion damage of metals or non-metals caused by microbial activities. SRB NRB Introduction Recovered from: https://www.blogdequk.com/2011/10/las-bacterias-sulfatorreductoras.html

3. The effect of methanogenic archaea (Methanococcus maripaludis) on corrosion behavior of 316L stainless steel under different concentrations of organic electron donor (acid acetic ) was investigated.

4. Methanococcus maripaludis It is mesophilic, meaning it grows under moderate conditions (20-45 degrees Celsius), and more specifically, its optimal growth temperature is 35-40 degrees Celsius. recovered from: http://wishart.biology.ualberta.ca/BacMap/cgi/getSpeciesCard.cgi?accession=NC_009135&ref=index_12.html

5. Materials and Methods In this study, the elemental composition of 316L is shown in table 1. The dimension of specimens used for surface analysis an electrochemical experiments is 10mm x 10mm x 3mm. Except for the working surface (1 cm2), all other surfaces of specimens were sprayed with waterproof paint.

6. Surface Analysis The biofilm on surfaces was characterized by a CLSM and a SEM. Prior to CLSM characterization, the specimens were rinsed with a phosphate buffer solution three times to remove planktonic cells and impurities on the surface and then stained with a fluorescent dye for 20 min in a dark room. Imagine to microscopy CLSM http://www.cnilaser.com/clsm.htm

7. Electrochemical experiments Were carried out in the three electrode system with a working electrode of 316L ss, an auxiliary electrode of graphite , and a reference electrode of Ag/AgCl. Images electrode Ag/AgCl and electrode graphite https://www.monografias.com/docs114/tecnicas-voltamperometricas/tecnicas-voltamperometricas

8. Result The figure shows the growth curves of M.maripaludis in culture media containing different acid concentrations with or without 316L. Image The growth curve M.Maripaludis https://www.blogdequk.com/2011/10/las-bacterias-sulfatorreductoras.html

9. Surface analysis Fig. Sem images of 316L in M.maripaludis media contain in 14 days

10. Fig SEM of 316L after removing corrosion products and tridimensional images of 316L after removing corrosion (a) and (b) in 14 d.

11. Fig SEM of 316L after removing corrosion products and tridimensional images of 316L after removing corrosion (c) and (d) in 14 d

12. The picture show the potentiodynamic polarization curves of 316L SS in M. maripaludis media containing different acid acetic concentrations for 14 d. The table show parameters of polarization curves of 316L SS in different media for 14 d (the potential is vs. Ag/AgCl, 3 M KCl) .

13. MA is a group of archaea that utilizes inorganic or organic compounds (hydrogen,acid acetic) to produce CH4 via anaerobic fermentation

14. Conclusion In organic electron donor deficient environment, M.maripadulis can utilize 316L as an alternative energy source to maintain growth. Metabolites from M.maripadulos lead tod acidification of the culture medium, wich is not the main reason for 316 corrosion. With decrease of organic electron donor concentration, corrosion of 316L is promoted, and more severe pitting corrosion of 316L is caused in M.maripadulis medium. M.maripadulis can secrete redox-active substances to the surrounding environments, wich provide the specific electron mediators for indirectly obtaining electrons from the steel.

15. References. https://www.blogdequk.com/2011/10/las-bacterias-sulfatorreductoras.html http://wishart.biology.ualberta.ca/BacMap/cgi/getSpeciesCard.cgi?accession=NC_009135&ref=index_12.html http://www.cnilaser.com/clsm.htm https://www.monografias.com/docs114/tecnicas-voltamperometricas/tecnicas-voltamperometricas

16. Thanks